Notes from the Field: Universal Statewide Laboratory Testing for SARS-CoV-2 in Nursing Homes - West Virginia, April 21-May 8, 2020.

Universal testing was conducted in all 123 West Virginia nursing homes, with 42 COVID-19 cases identified in 28 (23%) nursing homes;the 42 cases occurred in 11 residents (0 1% of residents tested) and 31 staff members Universal testing identified eight outbreaks with 17 staff members and five residents who tested positive for SARS-CoV-2, including six staff members and two residents who were asymptomatic The testing likely prevented the occurrence of ongoing transmission and larger outbreaks, had the asymptomatic infections gone undetected Proactive universal testing prevented additional infections, as illustrated by the lower percentages of residents and staff members with positive test results in outbreaks identified through universal testing compared with those identified through symptom screening Universal testing helped estimate the prevalence of COVID-19 in a population at increased risk for serious COVID-19 outcomes so that public health resources could be allocated to prevent further spread Statewide universal testing enabled rapid implementation of infection prevention and control measures that likely prevented the occurrence of larger outbreaks Since completing universal screening, West Virginia has maintained symptom screening in nursing homes, revised its outbreak case definition to constitute a single case in a nursing home, and adopted universal testing of all residents and staff members in response to an outbreak with weekly testing for a period of at least 14 days since the most recent positive result